绝对节点坐标法大型风力机复合材料叶片的动态特性

Dynamic Characteristics of Large Wind Turbine Composite Blades Using Absolute Nodal Coordinate Formulation

为研究大型风力机旋转复合材料叶片的非线性结构动态特性,采用绝对节点坐标法,并基于一般连续介质力学理论和复合材料本构关系,推导广义质量与刚度矩阵,建立大型风力机旋转复合材料叶片的非线性动力学模型。为描述叶片的转动,引入大范围转动连体坐标系,结合摄动原理及线性化方法,构建旋转叶片的状态方程。以非线性梁标准算例验证了模型的准确性,并以DTU-10MW风力机复合材料叶片为对象,分析了静止与旋转条件下的动态特性。结果表明,由于叶片的大型化和非线性变形特点,叶片静止时的挥舞、摆振和扭转振型存在显著耦合;由于动力刚化效应,叶片的各阶频率会随着转速的提高而改变,并对振型的挥舞和摆振产生较大影响。

To investigate the nonlinear structural dynamic characteristics of rotating composite blades in large-scale wind turbines,the absolute nodal coordinate method was used to derive the generalized mass and stiffness matrices based on the theory of general continuous media mechanics and the constitutive relationship of composite materials,and a nonlinear dynamic model for rotating composite blades of large-scale wind turbines was established.To describe blade rotation,a large-scale rotating body coordinate system was introduced,and the state equation of the rotating blade was constructed by combining the perturbation principle and linearization method.The model’s accuracy was verified using a nonlinear beam standard example,and the dynamic characteristics under stationary and rotating conditions of the DTU-10MW wind turbine composite blades were analyzed.The results showed that due to the blades’large scale and nonlinear deformation characteristics,there was significant coupling between the flapwise,edgewise,and torsional modes when the blades were stationary.Due to the dynamic stiffening effect,the frequencies of each order of the blades changed with the increase of rotation speed,significantly impacting the flapwise and edgewise modes.